Process for the recovery of oil from oil-bearing minerals



May 21,1957

PROCESS FOR THE RECOVERY OF' OIL FROM OIL-BEARING MINERALS OriginalFiled Sept. 16, 1948 INVENTOR." HARA?? 55s BY Y TTNEYS' PROCESS FR THERECOVERY OF OIL FROM DH1-BEARING MINERALS Harry V. Rees, Chappaqua, N.Y., assignor to Texaco Development Corporation, New York, N. Y., acorporation of Delaware Continuation of application Serial No. 49,581,September 16, 1948. This application December 29, 1952, `Serial No328,322

s claims. (ci. 4t2-197) This invention relates to a process for thetreatment of oil-bearing minerals. The process of this invention isapplicable to the treatment of such oil-bearing minerals as oil shaleand tar sands. In one of its more specitic aspects, this inventionrelates to a process for the generation of a mixture of carbon monoxideand hydrogen suitable as a source of gaseous fuel or as a source of`feed gas for the synthesis of hydrocarbons from oilbearing minerals.

An object of this invention is to provide an improved process for therecovery of hydrocarbon oils trom oil- 'bearing minerals.

Another object of this invention is to provide an improved process forthe recovery of hydrocarbon oils from oil shales.

'Still another object of the present invention is to provide an improvedprocess for the generation of car-bon monoxide and hydrogen fromoil-bearing minerals.

In U. S. Patent 2,735,787, a novel process is disclosed for heating andpulverizing solids. As disclosed in this patent, particles of solidmaterial are admixed with a vaporizable liquid to form a fluidsuspension or slurry. The suspension is passed as a conined streamthrough a heating zone wherein the liquid is Vaporized andthe solidparticles suspended in a stream of the vapor. Appreciable disintegrationof the solid particles results from this method of treatment. i

In accordance with this invention, particles of the oilbearing mineralsare mixed with a liquid to form a tluid suspension. The suspension is`passed through a heating zone wherein it is heated to an elevatedtemperature at least suiiicient to vaporize substantially all of thesuspending liquid. The liquid used yfor suspension should be one whichis vaporizable `and substantially inert or innocuous with respect tochemical reaction with the oil and mineral matter under the conditionsexisting in the heating zone.

Water and hydrocarbon oils are preferred liquids for use in the process.Oils which undergo thermal decomposition on heating to form vapors' andresidual carbonaceous solids are suitable for use in the process of thisinvention. Deposition ofcoke in the interior surface of the heating coilis minimized by the mechanical action ofthe solid materials.

Suitable liquids for use in the process of this invention include water;gasoline, kerosene, naphtha and gas oil fractions of petroleumdistillates; aromatic hydrocarbons, c. g., benzene, toluene; parains, e.g., hexane, heptane, etc.; naphthenes, e. g., cyclohexane,methylcyclohexane; and the like, and mixtures of these variousmaterials,An oil traction derived from they oil-bearing mineral itself may be usedfor making up the suspension.

In a preferred embodiment, the oil-bearing mineral in particle form isadniixed a liquid which may be converted to vapor form on heating. fThesuspension is passed Iunder conditions` of turbulent ow into a tubularheating zone wherein it is heated 'to a temperature at least" sufcientto lconvert all 'of the suspending liquid to vapor.

aired StatesA Pam o 2,793,104 Patented May 2,1, 195,7

Part or all of the resulting residual solid may be separated from theresulting vapors. Liquid. condensed from the vapors may be used in thepreparation of the slurry. The residual solid may be separated anddiscarded, or where combustible matter is still associated with thesolid, used for fuel or for the generation of carbon oxides andhydrogen. iIf desired, the dispersion of residual solid may be passed`directly to 1a combustion zone or gas generator `without separation.Residual unvaporized oil or carbonaceous solid associated with themineral residue is useful for the production. of a mixture of carbonmonoxide and hydrogen which may be used as fuel gas or 4as a source ofteed gas for the synthesis of hydrocarbons.

The quantity of liquid admixed with the mineral to form a uid suspensionmay vary considerably depending u-pon process requirements and the:composition of the feed material. A fluid dispersion in Water which maybe readily pumped, contains in excess of about 35 weigh-t percentliquid. The liquid content of the suspension may be controlled by iirstmixing the comiminuted mineral with `a quantity of liquid in excess ofthe desired quantity and adjusting the consistency to the desired valueby removal of excess liquid in a conventional thickener. The suspensionmay be readily pumped with suitable equipment, e. g., with a diaphragmtype pump, of the type normally used for handling similar suspensions ofsolids.

The particle size of the mineral fed to the heating zone should be suchthat the particles remain in suspension under conditions of turbulentIflow. Generally, it is preferable to use particles having an effectivediameter of less than about one-quarter inch. `Finer particle sizes areeven more readily handled. it is contemplated that in the usualapplica-tions of this process, expensive mechani- |cal pulverizationwill be unnecessary. tar sands, such as the Athabaslia tar sands,comprise inorganic mineral matter which is already of a particle sizesuch that it may be pumped through a heating coil.

in the processing of oil shales, the shale need be broken only intorelatively large lumps of a size such that they may be readily handledby the conventional conveying equipment. The s-hale is thendisintegrated, in accordance with the process of this invention, intoparticles of a size suitable for the forma-tion ofa suspension byheating it in oil in liquid phase under pressure whereupon the shale isdisintegrated to a particle size suitable for the formation of a fluiddispersion.

The temperature of the mixture of oil and shale tor disintegration ofthe shale should be within t-hc range of 'from about 700 F. to about 900F. The shale disintegrates more rapidly at the higher temperatures thanat the lower temperatures within said range. The pressure in the retortor zone in which the hot oil is contacted with the shale need 4besufficient only to insure the presence of oil in liquid phase in saidzone. Generally a pressure wit-hin the range of 400 to '1000 .poundsper` square inch is suitable for this purpose. Mechanical means may beemployed to aid in the disintegration of the shale and the formation ofa tluid suspension.

The suspension of mineral in liquid is heated by passing it through anexternally heated zone of restricted crosssectional area, most suitablya helical tubular heating zone. The heating may be carried out in afurnace such as is commonlyused for heating vapor streams in therefining of petroleum. The suspension is fed into the heated tube at arate suiiicient to cause turbulent flow and maintain dispersion of thesolid particles in the liquid. The linear velocity of the slurry at theinlet to the heating coil should be within the range of from about 1/2to 10 feet per second, suitably about 1 nto 2 feet per second. Thevelocity of the gaseous dispersion of residual solids Generally oil ordischarged from the heating coil should be within the range of about 25to 200 feet per second, suitably about 50 to 100 feet per second.

The temperature at the outlet of the heating coil may range from about500 to about l500 F. The temperature should be at least sucient toinsure substantially complete conversion of the liquid used forprepartion of the slurry to vapor. All of the oil :trom the oil-bearingmineral need not be vaporized; a heavy residual portion of the oil, forexample, or a carbonaceous solid residue, may 4remain on the sol-idparticles of mineral discharged from the outlet of the heating coil. Theextent of recovery of oil from the mineral, e. g., distillation ofVaporizable constituents therefrom, may be lcontrolled by cn trol of thetemperature and pressure at which the heating stepV is operated and thetime of contact between liquid and sol-id at elevated temperature. Thedistillation of volatilizable constituents is also dependent to someextent upon the amount and composition of the liquid used for formationof the slurry. Where water is used for the prepartion of the slurry, forexample, increasing amounts of water tend to increase the amount ofdistillation due to the well known partial pressure eects.

Pressure, in itself, is not critical in the heating step. Theinter-relationship of temperature and pressure with respect todistillation is well known. Generally, it is desirable to operate theheating step at a pressure near, or only slightly in excess, ofatmospheric pressure. In some instances, however, it may be desirable tooperate at pressures as high as 300 to 600 pounds per square inch, wherethe products of the heating step may be utilized etliciently at anelevated temperature and pressure. Considerable pressure drop takesplace in the heating zone due to resistance to How. This drop may be onthe order of magnitude of 100 pounds per square inch. Often it isdesirable to drop the pressure suddenly in the heating zone or at itsoutlet to increase the vaporization of volatile constituents ofthedispersion.

The separation of gases or vapors from a residual solid may be elfectedin a number of ways. A cyclone separator is generally effective forremoval of solids from gases. A liquid contact type gas scrubber iseffective for relmoval of part or all of the condensible vapors and moreor less powdered solid as desired from a gas stream. Other methods ofremoval include filtration and electrical precipitation.

Important advantages result from the method of recovering hydrocarbonoil from minerals in accordance with the process of this inyention. As adispersion or slurry, the oil-bearing mineral is readily transported andsubjected to elevated pressures. handled in a manner analogous tohandling of a liquid, troublesome lock hoppers and similar devices whichare normally required for handling solid materials are eliminated andreplaced simply by the slurry preparation equipment and pumps. Theslurry may be made up some distance from the processing site andtransported theretov by a pipeline. rl`he quantity of material fed tothe process may be accurately metered as a slurry of relatively constantcontrolled composition,

The invention will be more readily understood from the followingdetailed description and accompanying drawings. lt is to be understoodthat the detailed description of illustrative operations describespreferred embodiments of the invention and that the process of the.invention is not limited to the materials and methods speciticallydescribed.

Figure l is a diagrammatic flow sheet illustrating a preferred method ofapplying 'the process of the present invention to the extraction of oilfrom tar sands.

Figure 2 is a diagrammatic elevational View illustrating a vpreferredembodiment of the process of the invention as applied to the recovery ofhydrocarbon oils from oil shale. With lreference to Figure l, tar sandis mixed With water in a mixer 2 to form a slurry. The water and lsandare heated to a temperature sucient to insure ready Since the slurry maybe 4 mixing. Emulsifying agents or wetting agents may be used tofacilitate mixing. The slurry is passed by pump 3 through line 4 to aheating coil 6 disposed in furnace 7. In the furnace, the slurry isheated to a temperature sucient to vaporize all of the water.

The resulting mixture of vapors and residual sand is discharged into acyclone separator 9. Residual sand is withdrawn through line 10 fordisposal. The steam and hydrocarbon vapors are discharged from theseparator through line 11.

ln a typical operation, the slurry is passed into the heating coil at apressure of 400 pounds per square inch gauge and the temperature at theoutlet of the heating coil is 1000 F.

The hydrocarbon vapors and steam discharged from the separator throughline 11 are passed to a reaction zone 12 wherein they are reacted withoxygen to produce a mixture of carbon monoxide and hydrogen. Commercialoxygen containing in excess of percent by volume is preferred. Theoxygen is admitted to the reaction zone 12 through line 15. Product gasis discharged from the reaction zone through line 14 for use as fuelgas, feed gas for the synthesis of hydrocarbons, or the like. A portionof the vapor stream from line 11 may be passed through line 16 to themixer 2. These heated vapors supply heat in the mixer, aiding in theformation of a fluid dispersion of tar sand and water.

In a typical operation, oxygen concentrate containing in excess of 95percent oxygen by volume is supplied to the reactor 12. Reactor 12 isoperated at a temperature within the range of from about 200() to 2600F. The reaction zone contains a substantially unobstructed reactionspace so designed that the ratio of the internal surface of thereactionzone to the surface of a sphere of the same volume is less than 1.5.

With reference to Figure 2, oil shale in the form of relatively coarselumps is supplied to a lock hopper 26 through line 27. An inert gas issupplied to the hopper 26 through line 28 to build up the pressurewithin the hopper to the desired value. From the lock hopper the shaleis fed through conduit 29 and a rotary valve 30 into a retort 31. Oilfrom a suitable source enters the system through line 32 and is heated na heater 33 to a temperature sufficient to heat the shale to thedisintegration temperature. From the heater 33 the hot oil stream ispassed to retort 31 into contact with the shale.

Sufficient pressure is maintained in the retort to insure the presenceof oil in liquid phase. The hot oil stream supplies heat to the shale,dissolving the kerogen and disintegrating the shale to line particleswhich are entrained in the oil to form a slurry. The slurry of shaleparticles 1n oil is discharged from the retort through line 34, andpassed through a heating coil 36in heater 37 at a velocity sulcient toinsure turbulent flow in the heating coil.

In a typical operation, oil shale is broken into lumps about 1A inch indiameter and fed to the lock hopper 26 until it is lled. A gaseoushydrocarbon is then fed into the hopper through line 28 until a pressureof about 500 pounds per square inch is reached. The shale is then fedthrough rotary valve 30 into the retort 31 which is operated at apressure of about 500 pounds per square 1nch. Shale oil is heated to atemperature of 1000 F. in the heater 33 and passed into contact with thelumps of shale in the retort 31.

A stream of oil is recycled through line 38 to line 32. Part of the oilrequired for the retort may be supplied in this manner.

Slurry is fed to the heating coil at about 1 foot per second. In theheater 36 the oil is substantially completely vaporized forming adispersion of spent shale in oil vapors. The spent shale particles andhydrocarbon oil vapors are discharged from the heater coil through line41 into a cyclone separator 42. Spent shale is separated from the hothydrocarbon vapors and discharged through line 43. The hydrocarbonvapors pass through line 44 into a `gas generator 45 wherein `they arereacted with steam and oxygen to produce a mixture of carbon monoxideand hydrogen. Alternatively, the dispersion of shale particles inhydrocarbon vapors may be passed directly to the generator 45 throughline 46.

Oxygen is supplied to the generator through line 47 and the steamthrough line 48. Product gas is discharged from the generator throughline 49.

It will be obvious to those skilled in the art that the recoveredhydrocarbon vapors from the oil-bearing mineral in either of theabove-described preferred embodiments of the invention may find useother than as a feed for the production of carbon monoxide and hydrogen.The process of the present invention, however, is particularlyapplicable to reaction of the hydrocarbon from the oilbearing mineralswith oxygen and steam to produce carbon monoxide and hydrogen, and,hence, has been so described.

This application is a continuation of Serial No. 49,581, filed September16, 1948, now forfeited.

Obviously, many modifications and variations of the invention ashereinbefore set forth may be made without departing from the spirit andscope thereof and therefore only such limitations should be imposed asare indicated in the appended claims.

I claim:

1. In the recovery of oil from oil shale wherein a slurry of iineparticles of shale in a liquid hydrocarbon oil is heated to vaporize theoil content of the slurry, the improvement which comprises first formingsaid slurry by contacting a mass of oil shale consisting of lumps about1A inch and larger in diameter with a liquid hydrocarbon oil at atemperature in the range of about 700-900 F. effective to causedisintegration of said lumps into ne powder particles which suspendreadily in said liquid oil to form a slurry therewith, maintaining saidcontact for a sufficient period of time to form said slurry, withdrawingsaid slurry comprising suspended fine particles cntrained in said oil,passing said slurry into a tubular heating zone under conditions ofturbulent ow, vaporizing all of the suspending oil and the volatilizableportion of the oil from said shale in said heating zone to form adispersion of solid residue from said shale in oil vapors, dischargingthe resulting dispersion of oil vapors and solid residue from theheating zone, separating said vapors from the solid residue in saiddispersion, and subjecting said vapors to reaction with oxygen at anelevated temperature effective for conversion of hydrocarbons to carbonmonoxide and hydrogen.

2. In the recovery of oil from oil shale wherein a slurry of fineparticles of shale in a liquid hydrocarbon oil is heated to vaporize theoil content of the slurry, the improvement which comprises first formingsaid slurry by contacting a mass of oil shale consisting of lumps about1/4 inch and larger in diameter with a liquid hydrocarbon oil `at atemperature in the range of about 700-900" F. and a pressure in therange of from about 400 to about 1,000 pounds per square inch gaugeeffective to cause disintegration of said lumps into fine powderparticles which suspend readily in said liquid oil to form a slurrytherewith, maintaining said contact for a sufficient period of time toform said slurry, withdrawing said slurry comprising suspended fineparticles entrained in said oil, passing said slurry into a tubularheating zone under conditions of turbulent flow, vaporizing all of thesuspending oil and the volatilizable portion of the oil from said shalein said heating zone to form a dispersion of solid residue from saidshale in oil vapors, discharging the resulting dispersion of oil vaporsand solid residue from the heating zone, separating said vapors from thesolid residue in said dispersion, and subjecting said vapors to reactionwith oxygen at an elevated temperature effective for conversion ofhydrocarbons to carbon monoxide and hydrogen.

3. In the recovery of oil from oil shale wherein a f6 t slurry `of tineparticles of shale in a liquid hydroCilEbQ oil is heated to vaporize theoil content of the slurry, the improvement which comprises Viirstforming said slurry by contacting a mass of oil shale consisting oflumps about 1/4 inch and larger in diameter with a liquid hydrocarbonoil at a temperature in the range of about 700- 900 F. effective tocause disintegration of said lumps into fine powder particles whichsuspend readily in said liquid oil to form a slurry therewith,maintaining said contact for a sufficient period of time to form saidslurry, withdrawing said slurry comprising suspended fine particlesentrained in said oil, passing said slurry into a tubular heating zoneunder conditions of turbulent liow, vaporizing all of the suspending oiland the volatilizable portion of the oil from said shale in said heatingzone'to form a dispersion of. solid residue from said shale in oilvapors, discharging the resulting dispersion of oil vapors and solidresidue from the heating zone at substantially atmospheric pressure andat a temperature within the range of from about 500 to about 1,500 F.,separating said vapors from Athe solid residue in said dispersion, andsubjecting said vapors to reaction with oxygen at an ele` vatedtemperature effective for conversion of hydrocarbons to carbon monoxideand hydrogen.

4. In the recovery of oil from oil shale wherein a slurry of fineparticles of shale in a liquid hydrocarbon oil is heated to vaporize theoil content of the slurry, the improvement which comprises first formingsaid slurry by contacting a mass of oil shale consisting of lumps about1A inch and larger in diameter with a liquid hydrocarbon oil at atemperature in the range of about 700-900 F. ciective to causedisintegration of said lumps into line powder particles which suspendreadily in said liquid oil to form a slurry therewith, maintaining saidcontact for a sutiicient period of time to .form said slurry,withdrawing said slurry comprising suspended fine particles entrained insaid oil, passing said slurry into a tubular heating zone underconditions of turbulent flow, vaporizing all of the suspending oil andthe volatilizable portion of the oil from said shale in said heatingzone to form a dispersion of solid residue from said shale in oilvapors, discharging the resulting dispersion of oil vapors and solidresidue from the heating zone, and subjecting said dispersion toreaction with oxygen at an elevated temperature effective for conversionof hydrocarbons to carbon monoxide and hydrogen.

5. In the recovery of oil from oil shale wherein a slurry of tineparticles of shale in a liquid hydrocarbon oil is heated to vaporize theoil content of the slurry, the improvement which comprises rst formingsaid slurry by contacting in a contacting zone a mass of oil shaleconsisting of lumps about 1A inch and larger in diameter with a liquidhydrocarbon oil at a temperature in the range of about D-900 F.effective to cause disintegration of said lamps into fine powderparticles which suspend readily in said liquid oil to form a slurrytherewith, maintaining said Contact for a sufficient period of time toform said slurry, withdrawing said slurry comprising suspended iineparticles entrained in said oil, passing said slurry into a tubularheating zone under conditions of turbulent flow, vaporizing all of thesuspending oil and the volatilizable portion of the oil from said shalein said heating zone to form a dispersion of solid residue from saidshale in oil vapors, discharging the resulting dispersion of oil vaporsand solid residue from the heating zone, and separating said vapors from'the solid residue in said dispersion.

6. in the recovery of oil from oil shale wherein a slurry of tineparticles of` shale in a liquid hydrocarbon oil is heated to vaporizethe oil content of the slurry, the improvement which comprises firstforming said slurry by contacting in a contacting zone a mass of oilshale consisting of lumps about $4 inch and larger in diameter with aliquid hydrocarbon oil at a temperature in the 7 range of about 70D-900F. effective to cause disintegration of said lumps into tine powderparticles which suspend readily in said liquid oil to form a slurrytherewith, maintaining said contact for a sucient period of time to formsaid slurry, withdrawing said slurry comprising suspended fine particlesentrained in said oil, passing said slurry into a tubular heating zoneunder conditions of turbulent ow, vaporizing all of the suspending oiland the volatilizable portion of the oil from said shale in said heatingzone to form a dispersion of solid residue from Said shale in oilvapors, discharging the resulting dispar sion of oil vapors and solidresidue from the heating zone,

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separating said vapors from the solid residue in said dispersion andreturning at least a portion of the vapor constituents to saidcontacting zone as at least a portion of the hydrocarbon oilconstituting said slurry.

References Cited in the le of this patent UNITED STATES PATENTS1,447,297 Day Mar. 6, 1923 1,971,728 Perry Aug. 28, 1934 2,174,184Bywater Sept. 26, 1939 2,436,938 Scharmann et al Mar. 2, 1948

1. IN THE RECOVERY OF OIL FROM OIL SHALE WHEREIN A SLURRY OF FINEPARTICLES OF SHALE IN A LIQUID HYDROCARBON OIL IS HEATED TO VAPORIZE THEOIL CONTENT OF THE SLURRY, THE IMPROVEMENT WHICH COMPRISES FIRST FORMINGSAID SLURRY BY CONTACTING A MASS OF OIL SHALE CONSISTING OF LUMPS ABOUT1/4 INCH AND LARGER IN DIAMETER WITH A LIQUID HYDROCARBON OIL AT ATEMPERATURE IN THE RANGE OF ABOUT 700-900*F. EFFECTIVE TO CAUSEDISINTEGRATION OF SAID LUMPS INTO FINE POWER PARTICLES WHICH SUSPENDREADILY IN SAID LIQUID OIL TO FORM A SLURRY THEREWITH, MAINTAINING SAIDCONTACT FOR A SUFFFICIENT PERIOD OF TIME TO FORM SAID SLURRY,WITHDRAWING SAID SLURRY COMPRISING SUSPENDED FINE PARTICLES ONTRAINED INSAID OIL, PASSING THE SLURRY INTO A TUBULAR HEATING ZONE UNDERCONDITIONS OF TURBULENT FLOW, VAPORIZING ALL OF THE SUSPENDING OIL ANDTHE VOLATILIZABLE PORTION OF THE OIL FROM SAID SHALE IN SAID HEATINGZONE TO FORM A DISPERSION OF SOLID RESIDUE FROM SAID SHALE IN OILVAPORS, DISCHARGING THE RESULTING DISPERSION OF OIL VAPORS AND SOLIDRESIDUE FROM THE HEATING ZONE, SEPARATING SAID VAPORS FROM THE SOLIDRESIDUE IN SAID DISPERSION, A ND SUBJECTING SAID VAPORS TO REACTION WITHOXYGEN AT AN ELEVATED TEMPERATURE EFFECTIVE FOR CONVERSION OFHYDROCARBONS TO CARBON MONOXIDE AND HYDROGEN.